This invention relates to a cylinder head and camshaft arrangement for an internal combustion engine and more particularly to an improved cylinder head construction and arrangement for attaching it to a cylinder block.
As is well known, the performance of an internal combustion engine can be improved by using overhead valves and direct valve actuation by overhead mounted camshafts. In many high performance engines, multiple intake and exhaust valves and multiple camshafts are also employed. Although such constructions increase the performance of the engine, they also complicate significantly the construction of the cylinder head and particularly the manner by which it may be attached to the cylinder block. It is, of course, extremely important to insure that the clamping of the cylinder head to the cylinder block is uniform around the cylinder bore so as to insure against gasket failures and leakage. However, this problem becomes particularly acute when overhead camshafts are employed. That is, the placement of the hold down fasteners for the cylinder head can be comprised due to the use of the overhead camshafts.
In addition to the aforenoted problems, when overhead camshafts are employed it is frequently the practice to place the fasteners for the cylinder head to the cylinder block within the cam cover of the engine. This means that the cam cover must be removed to access the fasteners. In addition, frequently it becomes necessary to remove some of the valve train in order to access the fastener. In addition to the increased labor caused by such assembly methods, there is also the danger that when servicing the cylinder head fasteners that foreign material may enter into the valve train and cause eventual damage or wear. Since frequently it is the practice to require retorquing of the cylinder heads after a certain amount of running following rebuilds, the problems are not insignificant.
It is, therefore, a principal object of this invention to provide an improved overhead valve arrangement and system for fastening a cylinder head to the cylinder block.
It is a further object of this invention to provide a cylinder head construction that permits the cylinder head to be attached to the block without necessitating removal of any components of the valve train or with necessitating accessing the fasteners through the valve cover.
It is a further object of this invention to provide an improved overhead camshaft cylinder head assembly wherein the camshaft can be assembled and disassembled from the engine externally of the cylinder head and without requiring removal of any of the cylinder head assembly components